See versions history at the end of Ide_al4.al4

Unpack into D:\AL-IV\IDE_AL4 or edit options txt files before compiling.
If AL-IV is installed to another disk, unpack there.

_compile-... .cmd is to compile certain version of IDE AL4.
_compile-C#.cmd, _compile-C#final.cmd to compile C# version.
clear_projects.cmd is to clear all the versions compiled but first C# compiled version is moved to \Build subdirectory, use shortcut IDE_AL4.exe - Build to run such version.